Objects that are commonly present on the exteriors of motor vehicle bodies may be mounted using various mounting techniques. Some objects have shapes that fit to complementary shaped portions of a vehicle body without any additional means of attachment other than their particular shapes.
An example of such as object is an edge or corner molding that can simply snap onto a correspondingly shaped corner or edge. No fasteners or other means of attachment such as adhesive are needed to hold such a molding in place. However, depending on the materials of the molding and the body, and on how the molding fits to the body, the process of snapping the object onto a corner or edge may scratch or mar the finish of the body. A scratch that penetrates the full depth of the finish to bare metal would of course be especially undesirable.
Mechanical fasteners and fastening systems are traditional means of attaching objects to vehicle bodies. Screws inherently pierce the panel itself. When a fastener and the panel are both metals there is likely to be some exposure of metal, either on the exterior or the interior of the panel. While sealing of any exposed metal may be possible, such sealing typically involves an extra step, and even when performed, that extra step may not accomplish the desired objective if not performed with due care.
The use of adhesives to mount certain objects on bodies has gained increased acceptance over the years because of improvements in available adhesives that provide the tenacity and durability that are required for outside environments that are potentially subject to weather extremes of heat and cold and high and low humidity. Certain objects can be mounted by the use of such adhesives alone, and hence any risk of scratching or marring the surface finish of a vehicle body is essentially eliminated.
However, the beneficial properties of such adhesives may create other problems. An object that has a mounting face containing adhesive of great tenacity must be precisely placed before the object is moved against a vehicle body to place the adhesive in contact with the body. An adhesive that resists separation of the object from the body after such contact complicates removal of the object and its re-alignment and subsequent re-adhering to the body.
Some objects are mounted using a combination of adhesive and mechanical fastening. Undesired consequences such as those described above can still apply to such combined means of attachment.